Tunnel-kiln.



, J. 8, OWENS.

TUNNEL KILN.

APPLICATION FILED JUNE}. 19*" 1,251,273. Patented Dec. 25,1917.

nae 4 i'nz a lfar In the accompanying drawings:

Figure l is a half plan, half sectional View of so much of a tunnel kiln as will illustrate my invention; and

Fig. 2 a cross section on line 22 Fig. l.

The cars, having passed through a gradually increasing temperature in the kiln 1, approach the furnaces 2 as shown. by the arrow a. The ware after being subjected to maxiheat when. at the furnace 2, passes into the cooling portion 3 of the kiln, the cars finally emerging, at intervals, through the left hand end of the kiln which is closed by the door l.

in my earlier application I have set forth cooling means comprising either" a double wall or a plurality of independent air circulating ducts, the former arrangement being shown at 5, Fig. 1, and opening into the atmosphere at the top of the kiln by a number of ports 6. Outer air entering the space 5 at the bottom of the kiln, and also at points above the bottom, flows up'wa'cdly through the space and out through the ports 6. This air may be led'into ducts and used for various heating operations, or, it may escape into the atmosphere. The circulation is up ward and is a. natural draft. The heat radiated from the goods into the space 5 is carried off and cooling is thus eliccted.

The space 5 and ports 6 constitute no part of the present inyention, but are shown. and described to. distinguish my present improvements therefrom. a

The kiln is provided with a double wall beyond the furnaces 2 as shown at 7, there being an air space 8 within said wall which is completely sealed from the space 5 by a partition 9 of bribk so that there is-no air communication or interdependence between the spaces 5 and 8. The space 8 is provided at its upper end with ports 10 opening out into the atmosphere. Dampers or bricks,

certain ones of which are shown at 11, may

be employed. for regulating the intake of outer air into the ports 10. Were it not for the fact that the inner and outer walls of the air from the spaces 8 into the boxes 19.. Dis

posed within the boxeslQ and surrounded by the air space in said boxes, are the twyers 14 which communicate with the furnaces at 15 y in such manner that the flame will be directed into the furnaces. The twyers have ports or openings 16 which communicate with the manners interior of the air boxes. The openings 16 provide for an equal-distribution of the air from the air box into the twyer 14.

Gas or oil burners 17 are located so that they will discharge into the twyers 14. In showing the invention in connection with oil or gas burners, I wish it understood. that my invention is not limited thereto, as it play be carried out when coalis used as the uel.

If desired, the admission of air into the mouth 18 of the twyer 14 may be controlled by a suitable damper.

The travel of the heat is as indicated by the arrows b, that is, in opposition to the direction of the travel of the cars a.

The draft at the stack, not shown, causes outer air to dive down through the ports 10 as indicated by the arrows and to pass through the openings 13 into air boxes 12, thence through ports 16 into twyersj to combine with the flames and air entrained through the mouths of the twyers. The rela ,tively cool outer air absorbs the heat radiated from the are which has passed the furnaces 2 with a two-fold result. First, the'ware is cooled by being deprived of its heat through radiation, and, second, the air passing down through the spaces 8 has its temperature greatly heightened so that it combines with the flames from the burners l7 and the air entraining therewith to provide a more nearly perfect combustion in the furnace and cause the production'of an oxidizing fire as near as may be possible.

In my present invention, the cooling of the ware by absorption of the heat radiated therefrom is accomplished by the stack draft and the passage of the air is downward as shown in Fig. 2, as distinguished from the natural draft, which is upward in the spaces 5. Furthermore, the same air which is used for absorbing the heat radiated from the ware, performs the additional function of supporting combustion due to the heat it obtains from the ware and while subject to the draft at the stack.

Having thus described my invention, what I claim as new and desire to secure by Let ters Patent is l. A tunnel kiln having a. furnace, and a diving air circulating space in its well beyond the point of maximum heat derived from the furnace, said space having an airreceiving mouth at its upper part and being in communication with the furnace at its lower part, the air space being separated from the interior of the kiln by a single wall through which the heat radiated from the ware after the latter has passed the furnace and,attained its maximum heat passes directly to said air space for absorption by the air in said. space, the draft on the kiln causing air in said space to pass to the furnace, thereby cooling the ware and. supplymamas Lag the furnace with heated air to support combustion.

2. A tunnel kiln having a, furnace, a douhle Wall provided with an air circulating space open to the outer air at its upper part, an air box with which said air circulating space communicates at a point lower down, a twyer open to the outer air and opening into the furnace, said twyer having ports 10 communicating with the air box, and a burner adaptedi'to discharge into the twyer, the stack draft on the kfln serving to draw outer air into the air box and twyer and In testimony whereof, I hereunto atfix my slgnature. Y

JOHN B. OWENS. 

